Apparatuses are known for dispensing various paint colours and the like in predetermined volumes into a paint container whereby to produce a desired color paint. Such apparatuses are, for example, described in U.S. Pat. Nos. 5,474,211 and 5,558,251. Containers containing different color paints are mounted on a turn table with each of the containers being identified. The desired containers are then rotated to position same at a discharge location where a predetermined quantity of paint is discharged through a metering valve apparatus. A metering pump is usually provided at the dispensing station and by controlling a discharge cycle a certain volume of paint is released. A disadvantage of this type of equipment is that it is very costly to fabricate and requires frequent maintenance as the valves and discharge port are of complex construction and this causes small paint residue to lodge itself in irregular spaces where it hardens as it is usually maintained stagnant for long periods of time between uses. Also, these paints are most often contained in containers which are maintained stationary and the heavier paint molecules settle to the bottom of the paint mixture and therefore the composition of the mixture may vary between uses.
When dispensing colored liquid printing ink from containers for commercial use, it is desirable to maintain the ink and its coloring agent in a substantially homogeneous condition. This is particularly so as the coloring agent has a specific gravity greater than that of water and has a tendency of settling to the bottom of the container. Also, every color has its own chemistry and the specific gravity of the various chemicals differ between different colors. Another problem with prior art devices is that there is a requirement to fill the containers in the dispensing machine with pigments which are transported in another container, usually metal containers. Accordingly, it is firstly necessary to mix the coloring agent within the transport container and then place the mixed color into designated ones of the containers permanently secured in the machine. If the ink is not stirred properly then the composition thereof will vary as the machine containers are filled from time-to-time. This is also expensive in that additional transport containers need to be provided.
Containers of the prior art are usually metal containers and many are reusable. Accordingly, they require cleaning.